Vascular occlusion devices such as atrial septal defect closure devices are used for closing defects or holes in the vascular system of a body. Such devices usually include an occluding member which is dimensioned larger than the hole, and some technique for mounting the occluding member to the tissue proximate the defect or hole.
The devices are typically made of a wire frame or skeleton which can become fatigued or perforate the tissue wall. It is also desirable to center the device within the hole and provide a stable technique for keeping the device securely mounted to the tissue.